The present invention relates a tool for installing coaxial cable connectors on conventional coaxial cables.
Coaxial cables are used extensively for carrying signals to a variety of common devices such as televisions, VCRs, cable converters, radio systems and the like. Typical coaxial cables include a centrally located inner electrical conductor surrounded by an outer electrical conductor that is inwardly spaced relative to the inner conductor. A dielectric insulator is positioned between the inner and outer conductors. The outer conductor is protectively surrounded by a dielectric jacket. Conventionally, the inner conductor is made of a conductive wire while the outer conductor forms a sleeve made of a sheet of fine braided metallic strands, a metallic foil or multiple layer combinations of either or both.
Coaxial cables are typically provided with coaxial cable connectors mounted at each longitudinal end thereof. The connectors are adapted to be threaded into a complimentary interface port so as to electrically connect the coaxial cables to the various electronic devices. Most conventional coaxial cable connectors have a generally tubular configuration defining a connector front end carrying an appropriate fastener designed to mate with the equipment ports or terminals. The conventional cable connectors typically also define a rear end having either a single inner sleeve or inner and outer radially spaced open-ended concentric sleeves. When two concentric sleeves are used, the inner sleeve is configured so as to be insertable into the specific section of the coaxial cable in electrical contact with the outer conductor and electrically insulated from the inner conductor by means of a dielectric insulator. The outer sleeve is gripped to securely couple the connector to the cable and to achieve an electrical ground connection and weather seal.
Although conventional coaxial cables and conventional coaxial cable connectors adequately perform their respective functions, they collectively suffer from at least one major drawback. Indeed, although well designed for their individual intended purpose, they are rather difficult to assemble.
Mounting a conventional cable connector to a conventional coaxial cable involves a set of steps which require a good amount of force to be manually applied, without compromising the precision of the operation. In order to insert a coaxial cable connector with onto the free end portion of a coaxial cable, an individual must first strip away a predetermined length of outer conductor and dielectric insulators to leave only a predetermined length of inner conductor protruding from the end section of the coaxial cable. The individual must then secure with on hand the end section of the coaxial cable and use the other hand to force the inner sleeve of the connector into the cable end with the sleeve operatively engaging the outer conductor. When an outer sleeve is used, a crimp tool is used to crimp the outer sleeve on the outer surface of the protective jacket. This operation not only requires manual dexterity but is also tedious and time consuming. Furthermore, the relatively small cable connector is difficult and awkward to manipulate thus potentially leading to improper engagement of the connector with the conductive components of the coaxial cable. Furthermore, the relatively sharp edges of the connector and/or pointed tip of the conductors may puncture the skin of the installer thus potentially causing injury.
Grasping of both the connector and the cable reduces the accuracy of the mounting operation, which requires a certain degree of precision for providing optimal contact between the connector and the coaxial cable. Furthermore, small angular deviations of the connector axis relative to the coaxial cable axis may render the connection inoperative. Also, the length of the stripped portion of the inner conductor must be gauged accurately so that a predetermined length of inner conductor protrudes from the connector once the latter is mounted on the cable.
It is important to note that properly mounting a cable connector to the free end portion of a coaxial cable, is not a simple task: it requires a good deal of manual dexterity, to combine proper precision for ensuring a suitable connection between the connector and coaxial cable, with applying a sufficient force required to insert the cable connector stem between the alternating insulating and conductive layers of the coaxial cable free end portion against the friction of the resilient insulating material on the connector stem.
U.S. Pat. No. 4,244,067 issued in 1981 to R. D. Rowe, shows a tool in the form of a pair of pliers, including two arms or handles which are each provided with a coextensive cutting element. The two cutting elements together form a jaw, with cutting edges inwardly oriented in the jaw, for cutting or stripping a cable. The lower end of one of the handles of the Rowe pliers is provided with a threaded free end portion which further includes a central channel. This threaded free end portion is destined to be threadingly engaged by a cable connector, for temporarily fixing the cable connector to the cable.
FIG. 6 of the annexed drawings shows the Rowe pliers 100 in an opened condition, i.e. with the two arms 102, 104 being spread in their opened limit position. A cable connector is destined to be temporarily fixedly installed on the lower threaded end portion 106 of arm 102. Arms 102, 104 are pivoted at 108 to allow jaw 109 to be selectively opened, thus separating the cutting elements 110, 112 and their respective cutting edges 114, 116.
Arrow A1 in the annexed FIG. 6 shows the intended direction of the pressure to be applied on a cable connector to operatively install same on the outer free end portion of a coaxial cable. This direction is aligned with the general longitudinal axis of the first arm or handle 102. By manually grasping either one of the two handles 102, 104 or both handles 102, 104 simultaneously, a person can insert the cable connector onto the outer free end portion of the coaxial cable, without directly manually holding the small cable connector. For example if only first handle 102 is grasped as shown by the position of the hand H in FIG. 6, one can squeeze the handle with his fingers, and then axially push the cable connector onto the cable free end portion. If both handles 102, 104 are grasped, handles 102, 104 are then in a closed position (as shown for example in FIG. 3 of the Rowe patent), and the hand position is similar to that of hand H in FIG. 6 of the annexed drawings, although the hand will be more opened to fit around the spaced-apart pair of handles 102, 104.
In any event, the pressure applied by the hand must be applied according to the direction of arrow A2, i.e. aligned with the intended direction in which the connector is to be pushed. This is likely to result in the hand sliding along the handle 102 if only handle 102 is held, or around handles 102, 104 if both handles are held. Indeed, only the friction resulting from the hand being forcefully closed onto handle 102 or handles 102, 104 will prevent the sliding of pliers 100 in the hand. Furthermore, if only handle 102 is grasped, it will become difficult to apply sufficient pressure thereon to frictionally prevent the handle 102 from sliding, considering the small diameter of handle 102. If both handles 102, 104 are grasped, then in addition to the above-mentioned problem, it will also become difficult to prevent a slight angular deviation of the cable connector relative to the coaxial cable to occur while it is being installed, due to the fact that the tool will not be symmetrically aligned relative to the connector and cable free end portion, and consequently the tool is likely to pivot about threaded end 106 when downward pressure is applied while both handles 102, 104 are being held.
To attempt preventing the hand from sliding on pliers 100 when the connector is being installed, one could try holding the transverse second handle 104 while pliers 100 are in an opened condition, as shown by the alternate position Hxe2x80x2 of the hand in the annexed FIG. 6. Arrow A3 shows that the hand still forces the pliers along the direction of threaded end portion 106, to properly install the cable connector, while the transversely positioned handle 104 is not aligned with first handle 102, thus effectively reducing the likelihood of the hand sliding therealong. However, as shown in FIG. 6, this will result in handle 104 pivoting about pivot 108 towards its closed position, thus effectively preventing installation of the cable connector by holding the pliers in this way. To circumvent this, the fingers could be positioned between handles 102, 104 close to pivot 108 as shown with hand Hxe2x80x2, but the person""s fingers would then be squeezed between the arms 102, 104 under the pivoting movement second handle 104 towards its closed position.
It is understood that it is impossible for a person to hold the handle 104 on either side of pivot 108 to apply, pressure in the direction of handle 102 with his palm, since the person""s palm would then be applied against the pointed tip 118 of cutting element 112, and also against the upper free cutting edge 116 of cutting element 110, thus effectively cutting into the person""s hand. Furthermore, should the jaw 109 close itself while the person""s fingers or hand is located between edges 114, 116, important wounds are likely to occur. Consequently, this alternate way of grasping pliers 100 is not a viable option.
If only one of the two handles 102, 104 is grasped for inserting the cable connector onto the cable free end portion, the other free handle is likely to become cumbersome and annoying, since it will be allowed to freely pivot at all times, when the pliers are handled.
Thus, although the Rowe patent does show a tool for installing a cable connector on a coaxial cable, the Rowe tool is not believed to be an efficient tool for installing cable connectors on coaxial cables. It is understood that Rowe does provide a pair of multifunctional pliers that can be used for accomplishing a number of different tasks related coaxial cables, but that these multiple functions of the Rowe pliers are a detriment to the efficiency of the particular coaxial cable connector installation function.
It is an object of the present invention to provide a tool facilitating the mounting of coaxial cable connectors on conventional coaxial cables.
It is a further object of the present invention that the tool allows for easy and ergonomic mounting of a conventional coaxial cable connector on the end section of a conventional coaxial cable.
It is a further object of the present invention that the tool reduces the risk of damaging both the connector and the cable, and increases the accuracy of the connection and thus improves the electrical properties of the assembled cable-connector combination.
It is yet another object of the present invention that the tool reduces the amount of time required for mounting the connector to the cable and the amount of manual dexterity required for performing the operation.
It is another object of the present invention that the tool reduces the risk of injury related to the assembly operation and ensures relatively constant achievement of a proper contact that will withstand frequent use and connect-disconnect cycles.
It is an important object of the present invention that the tool allows one to forcibly install the cable connector in the coaxial cable by applying direct pressure on the tool with the flat palm portion of his hand, to prevent the tool from sliding in the person""s hand and to allow for a greater force to be exerted by the person.
The present invention relates to a tool for mounting a cable connector of the type having a hollow connector stem defining an inner channel and a connector fastening sleeve carried by and coextensive with the connector stem, to the free distal end portion of a coaxial cable of the type having an outer open-ended sleeve member and an inner conductor inside the cable sleeve member, with the inner conductor having a protruding portion axially protruding out of the cable outer sleeve member, said tool comprising:
an integral, rigid T-shaped handle defining a straight elongated grasping segment and a second straight elongated spacing segment originating and integrally extending perpendicularly from an intermediate portion of said grasping segment and having a free extremity opposite said grasping segment, wherein the perpendicular orientation of said grasping segment relative to said spacing segment of said handle is permanent;
a tool fastening sleeve fixedly and coextensively attached to said spacing segment free extremity, said tool fastening sleeve having an outer surface sized and configured for complementary engagement with the connector fastening sleeve, said tool fastening sleeve further having an inner channel sized for sliding engagement therein of the protruding portion of the cable inner conductor;
an attachment member provided on said tool, for releasably fixedly attaching said connector fastening sleeve to said tool fastening sleeve;
wherein the cable connector can be removably attached to said tool fastening sleeve by engaging the connector sleeve onto said tool fastening sleeve with said attachment member operatively inter-connecting said tool and the connector.
Preferably, said attachment member on said tool fastening sleeve is a thread, for threadingly engaging a complementarily thread on the connector fastening sleeve.
Preferably, said handle is provided with a stripping blade for stripping a section of the cable sleeve member away from said inner conductor for creating the inner conductor protruding portion, said stripping blade being mounted on said handle.
Preferably, said handle is provided with an aperture in which said stripping blade is mounted so as to extend partially across said aperture.
Preferably, said stripping aperture defines a stripping aperture blade mounting edge and an opposed stripping aperture cable abutment edge, said blade extending from said blade mounting edge in an inclined fashion relative to said cable abutment edge.
Preferably, said cable abutment edge is provided with grooves formed thereon.
Preferably, said handle includes a gauging aperture extending therethrough, said gauging aperture having a complete cable receiving section configured and sized for receiving the cable outer sleeve member and an inner conductor receiving section configured and sized for receiving the inner conductor protruding portion, said complete cable receiving section and said inner conductor receiving section defining an abutment shoulder for the axial abutment thereon of the sleeve member of the cable free end portion thus allowing gauging of the length of the protruding portion of the inner conductor.
Preferably, said grasping segment defines a generally rectilinear palm contacting section and an opposed wavy finger contacting section formed with grooves sized and shaped to receive the hand""s fingers therein.
Preferably, said tool further comprises a hooking aperture extending transversally through said grasping segment.